Search PubMed⌕ Search

Biomedical subjects

H Sakurada

Publications and source records attributed to H Sakurada.

At least 55 records · Page 3Linked to original sources
PubMed1991

Association of humps on monophasic action potentials and ST-T alternans in a patient with Romano-Ward syndrome.

A case of Romano-Ward syndrome had episodes of torsade de pointes preceded by ST-T alternans. ST-T alternans was induced by isoproterenol and abolished by verapamil, lidocaine, mexiletine and MgSO4. A monophasic action potential (MAP) showed humps in MAPs at the right ventricular outflow tract but not at the right ventricular apex in alternate beats. Differences in the MAP duration were noted between the two areas and were associated with ST-T alternans. Atrial pacing abolished both humps and ST-T alternans. These results suggest that humps are a possible reflection of early afterdepolarizations and their appearance is limited to localized regions of the ventricles, which produces regional disparity of repolarization and ST-T alternans.

Action Potentials↗
PubMed1990

The role of electrophysiologic study for prediction and treatment of life-threatening arrhythmias.

The prognostic significance of drug therapy based on the electrophysiologic study (EPS) was examined during a mean follow-up period of 32 months in 45 patients with sustained ventricular tachycardia (SVT) and in 87 with nonsustained VT (NSVT), and in 7 survivors of cardiac arrest. The drug treatment during the follow-up period was divided into EPS-guided therapy and empirical therapy; in the former therapy, an effective drug for prevention of induced VT by EPS was given and in the latter therapy, an empirical drug was used because there was no effective drugs by EPS. Occurrence of SVT or sudden cardiac death was considered as an arrhythmic event. Of 45 patients with SVT, Group I consisted of 32 cases with organic heart disease (OHD) and Group II, 13 without OHD. In Group I, arrhythmic event occurred in only 2 of 15 patients with EPS-guided therapy, whereas 9 of 13 cases with empirical therapy had arrhythmic event (p less than 0.01). In Group II, no arrhythmic event was observed in the 9 patients with EPS-guided therapy, whereas it was seen in 3 of the 4 patients with empirical therapy (p less than 0.05). Of 87 patients with NSVT, 61 cases had OHD (Group III). SVT was induced by EPS in 13 patients in Group III. Arrhythmic event was not observed in 8 patients with EPS-guided therapy, whereas it was seen in 3 of the 5 patients with empirical therapy (p less than 0.05). Arrhythmic event occurred in 2 survivors of cardiac arrest who underwent empirical therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Effects of oral flecainide treatment of refractory tachyarrhythmias].

Oral flecainide treatment was given to five patients who were refractory to conventional antiarrhythmic agents. The five patients included one with atrioventricular reentrant tachycardia (AVRT), one with non-sustained ventricular tachycardia (nsVT) and three with sustained VT (sVT). Flecainide produced favorable responses in patients of AVRT, nsVT and sVT with arrhythmogenic right ventricular dysplasia (ARVD). In the case of AVRT, flecainide exhibited a preventive effect on tachycardia induced by programmed electrical stimulation (PES). In the case of nsVT, flecainide markedly reduced the number of VPC and abolished the VT on the Holter ECG. In the case of sVT with ARVD, sVT was not induced by PES after the flecainide. Long-term treatment with flecainide on these three cases produced complete prevention of tachycardias. As an adverse effect of flecainide, an aggravation of congestive heart failure was recognized in one case with cardiac sarcoidosis. PQ interval and QRS interval in all the cases were prolonged after flecainide. The results indicate that flecainide is a useful antiarrhythmic agent for tachyarrhythmias refractory to treatment with conventional drugs.

Administration, Oral↗
PubMed1989

A clinicopathologic study of the accessory bypass tracts in six cases of Wolff-Parkinson-White syndrome.

A clinical and histologic correlation study was conducted to examine the accessory bypass tracts in 6 cases of Wolff-Parkinson-White syndrome. (1) Types A, B (Rosenbaum) and C (Ueda) were found in 2 cases each. From the polarity of the delta waves, the site of the bypass tract was assumed to be in the left posterior and left lateral free wall in type A, the right lateral and right posterior paraseptal regions in type B and in the right posterior paraseptal and right anterior paraseptal areas in type C. (2) In 6 cases 19 bypass tracts were found, consisting of 18 Kent bundles and 1 Mahaim fiber, from a total of 146,400 serial sections. The site of the bypass tract was the left lateral and left posterior walls in 2 type A cases, and the right lateral and right posterior walls in 2 type B cases, with good correspondence to our assumption. In both type C cases it was biventricular, composed of left posterior paraseptal and right lateral regions with an additional Mahaim fiber in 1 case. (3) A total of 46 cases of WPW syndrome were collected from the literature and the present paper; they consisted of 16 cases of type A, 20 of type B, 4 of type A + B and 6 of type C. Seventy % of type A cases showed a bypass tract in the left heart, and 64% of type B in the right heart. In 6 cases of type C, the bypass tract was found in various sites and in various combinations, requiring further investigation.

Adult↗
PubMed1989

[Lassa fever associated with effusive constrictive pericarditis and bilateral atrioventricular annular constriction: a case report].

A case of Lassa fever associated with effusive constrictive pericarditis and bilateral atrioventricular annular constriction was reported. A 49-year-old man, who had been diagnosed by indirect fluorescent antibody test as the first case of Lassa fever in Japan, was referred to the Hiroo Hospital because of syncope, progressive hepatomegaly, ascites and pericardial effusion in spite of pericardiocentesis and corticosteroid therapy. On admission, his blood pressure was 92/60 mmHg and he had a paradoxical pulse. Two-dimensional echocardiography revealed a localized pericardial effusion adjacent to the right ventricular wall and behind the left ventricular posterior wall. Bilateral atrioventricular annular constriction was also present. On pulsed Doppler echocardiography, the peak inflow velocities of the right and left ventricles increased during atrial systole. Right heart catheterization revealed a mean diastolic pressure gradient of 8 mmHg across the tricuspid valve. After pericardiectomy, a diastolic dip and plateau pattern became evident in the right ventricular pressure tracing, suggesting the presence of residual constriction. However, the atrioventricular annular constriction was no longer evident on two-dimensional echocardiography. This is considered the first reported case of subacute effusive constrictive pericarditis caused by Lassa fever.

Cardiac Catheterization↗
PubMed1988

Intracoronary urokinase in acute myocardial infarction: prevalence of total coronary occlusion during the early hours, effects on myocardial infarct size and left ventricular function, and outcome of residual coronary stenosis.

The effects of intracoronary thrombolysis (ICT) were studied in 88 acute myocardial infarction patients. Total coronary occlusion was observed in 67 of the 88 patients (76.1%) who were evaluated within 6 hours of the onset of symptoms. Among these 67 patients 42 (62.7%) were successfully recanalized by intracoronary urokinase. The recanalization rate was higher in the lesion at the left anterior descending artery, in younger patients (49 years or less) and in patients with a shorter history of pre-infarction angina. Eight of 11 patients (72.7%) with subtotal coronary occlusion and 17 of 35 patients (48.6%) with recanalization after ICT showed spontaneous regression of the residual coronary stenosis at the chronic stage angiography. There was no re-occlusion in the subtotal occlusion group and only 6 cases of re-occlusion (17.1%) in the recanalization group. The majority of re-occlusions progressed from the lesion with 99% residual stenosis and delayed filling. Accordingly the true value of additional percutaneous transluminal coronary angioplasty would be limited to the latter cases. Reduction in infarct size and improvement in left ventricular function were limited to those patients with incomplete or subtotal coronary occlusion and were not seen in cases with total obstruction which was recanalized by ICT.

Adult↗
PubMed1984

[Transient obstruction of the left ventricular outflow tract induced by excessive alcohol intake: a case report].

A case of transient obstruction of the left ventricular outflow tract after excessive intake of alcohol was reported. This 41-year-old man was admitted to the Hiroo Hospital because of a syncopal attack experienced while walking. He had been drinking excessively for one week until the day before admission. On admission, physical examination revealed a bifid carotid pulse and a grade 3/6 systolic ejection murmur accentuated by Valsalva maneuvers and prompt standing. The second heart sound was paradoxically split. Echocardiography showed typical systolic anterior motion of the mitral valve (SAM). The interventricular septal and left ventricular posterior wall thicknesses were 13 mm and 11 mm, respectively. No enlargement or displacement of the papillary muscles was noted. The redundant mitral chordae tendineae protruded into the left ventricular outflow tract in systole, and both the anterior and posterior mitral valve leaflets were retracted upwards approximating the interventricular septum by these chordae, resulting in obstruction of the left ventricular outflow tract. All signs of left ventricular outflow obstruction, including SAM, disappeared within several days after admission, and prolapse of the anterior mitral leaflet became evident. Since ejection fraction was markedly increased and the corrected QT interval was prolonged on admission, this patient was considered to be in hyperadrenergic state induced by excessive alcohol intake. In this case, left ventricular outflow tract obstruction was attributed to hyperadrenergic state and a redundant mitral apparatus.

Adult↗
PubMed1981

Polysomnographic study of terminal sleep following delirium tremens.

Polysomnographic recording was performed during terminal sleep following delirium tremens (DT) in nine chronic alcoholics. After terminal sleep all the alcoholics fully recovered from DT. The duration of terminal sleep and DT differed among patients, but no significant correlation was found between the two. The most prominent feature in teh different stages of terminal sleep was a considerable decrease in slow wave sleep, especially stage 4 sleep. A slight decrease was observed in REM sleep, while stages 1 and 2 increased. A small amount of stages 1-REM and 2-REM was observed and a statistically significant correlation was noted between the appearance of these sleep stages. Intermittent wakefulness occurred in many patients. The disappearance of sleep cycles was observed in some patients. Therefore, terminal sleep following DT probably consists of recovery sleep from sleep deprivation caused by DT and disturbances of consciousness. Sleep cycles regularly occur in the former, but not in the latter.

Adult↗
PubMed1980

Study on the effects of L-5HTP on the stages of sleep in man as evaluated by using sleep deprivation.

The effects of L-5HTP 200 mg on the EEG sleep pattern were investigated in normal subjects. When L-5HTP 200 mg was orally administered, only % S1 significantly decreased in comparison with the baseline. There was no change in any sleep stage on the first recovery night. On the second recovery night, % S1 significantly decreased, while % SR increased significantly. SWS did not show any change. The effects of L-5HTP 200 mg were investigated on the first recovery night after one night of sleep deprivation. SWS significantly increased on the first recovery night when a placebo was given, while this rebound increase of SWS disappeared and % S2 significantly increased on the first recovery night when L-5HTP was given. % SR significantly increased on the next night after the L-5HTP night.

5-Hydroxytryptophan↗
PubMed1980

The sleep pattern of chronic alcoholics during the alcohol withdrawal period.

The sleep pattern of 13 alcoholics was recorded for five consecutive nights after the cessation of alcohol intake. In six of the 13 patients, delirium tremens occurred after hospitalization. A decrease of total sleep time and slow wave sleep was more pronounced in the patients with delirium tremens than in those without. REM sleep had slightly decreased in both groups. Rebound increase in REM sleep had not been observed in all the patients with delirium tremens. Stage 1-REM with tonic EMG was observed in these two groups. From these results we are inclined to hypothesize that a deficiency of cerebral 5-HT in alcoholics may lead to a pronounced decrease in slow wave sleep, with rapid eye movements appearing in stage 1 sleep.

Adult↗